Fluid viscosity control



Oct. 11, 1966 NUN- MAGNETIC TAPERED 705E RELRY LE ROY F. DEMING FLUIDVISCOSITY CONTROL Filed Dec. 22, 1961 ELEC. Pow R SUPPLY EL E C POWERSUPPLY IVO/V- MA ENE 77C T/VPE RE D TUBE CONSTANT SPEED MOTOR F/eJ.

IN VEN TOR.

LEROY F: Dem/vs 4 I'TORNEY United States Patent 3,277,916 FLUIDVISCOSITY CONTROL Le Roy F. Deming, 1512 17th St. N., Arlington, Va.Filed Dec. 22, 1961, Ser. No. 161,746 6 Claims. ((11. 137--87) Theinvention described herein maybe manufactured and used by or for theGovernment of the United States of America for governmental purposeswithout the payment of any royalties thereon or therefor.

This invention relates to viscosity controls for liquids andparticularly to regulators for controlling the quantity of heat energysupplied to a fluid system whereby the viscosity thereof may bemaintained at a predetermined quantity or level.

Optimum performance of pressure atomizing oil burners and optimumconditions of combustion in diesel engine cylinders is dependent uponuniform atomization of the fuel oil. The extent of atomization (size ofthe globules) of the fuel oil is determined by the viscosity of the fueloil and the pressure difference between the supply side of the atomizingorifice and the combustion chamber. For refined petroleum products, theviscosity does not vary widely, particularly while a single grade offuel oil is supplied. For residual fuels, however, there is a widevariation in the viscosity. Seldom do two successive deliveries haveidentical viscosities and, in some instances, settlement of heavierfractions results in viscosity variations between the time the supplytank is well filled and the time it approaches an empty condition.

The viscosity of residual hydrocarbons and even of most refinedhydrocarbons is a function of temperature which temperature, in modernhigh rate fuel burning installations, must be closely and continuouslycontrolled and monitored to produce a constant viscosity of the fueloil. Any variation is viscosity at the burner or diesel cylinderinjectors induces a loss in efficiency.

Surprisingly few such controls, i.e., viscosity monitored, continuoustemperature controls, are found in the prior art. That shown by Smith inPatent No. 1,654,614 is based on a pressure-operated electromechanicalcontrol of the heating medium. There, the pressure-operated sensor islocated directly in the burner feed line and the electromagnetic valveis regulated either full on or full off. These features would seem topossess certain disadvantages leading to a possible cyclic variation inthe viscosity of the fuel oil which, in itself, would result in areduced efficiency.

The principal object of my invention, therefore, is to provide a fluidviscosity control which has none of the disadvantages of those in theprior art and will maintain the operation of those devices served by thefluid at maximum efficiency.

Another object of my invention is to provide a fluid viscosity controlthat will operate purely as a function of the viscosity of the fluidbeing used.

A further object of my invention is to provide a fluid viscosity controlwherein the fluid viscosity sensor is ancillary to the main flow offluid in the operating system and does not impede the flow of fluid tothe operating devices.

A still further object of my invention is to provide a fluid viscositycontrol such that when the control means or sensor has been adjusted orset for a predetermined fluid viscosity, that viscosity will bemaintained within close limits.

Other and further objects and advantages of my invention will beappreciated in the study of the following detailed description andaccompanying drawings wherein:

FIGURE 1 is a schematic layout of a fluid system employing my viscositycontrol; and

3,277,916 Patented Oct. 11, 1966 FIG. 2 is a schematic diagramillustrating a modified form of viscosity control.

With reference to FIG. 1, fuel oil service pump 10 draws fuel oil from atank or other source of supply (not shown) and pumps it into a fuel oilheater 14 through a pressure controlled by-pass valve 11. Thepressurecontrol 12 is installed in by-pass line 13 which taps into themain line 18 beyond the oil heater at fitting 15. As in the usualinstallation, when the pressure drops off at the fitting 15 due to astoppage in the heater, the differential pressures developed in thepressure-control 12 opens the by-pass valve 11 and allows the fluid toflow around the defective oil heater.

The fuel oil heater 14 is provided with the usual heating fluid supplyand return lines 19 which deliver the heating fluid from a supply source(not shown) to the oil heater. An electric motorized control valve 20 isinstalled in the heating fluid delivery line which valve and itsfunctioning will be described later.

The heated fuel oil passes from line 18 into a header 21 from which asupply of fuel oil is fed to a plurality of burners 22 which areprovided with the usual valves 23. From header 2 1, line 24 leads backinto the fuel oil tank or fuel oil pump suction to return the unused oilthereto. Line 24 is provided with control line tap fitting 25, fuel oilreturn control valve 26 and control line return fitting 27.

Control line 28 leads from tap fitting 25 through a control line valve29, and a bypass fitting 30 to a positive displacement type meteringpump 32 which is driven by a constant speed motor 34 which is activatedfrom a constant source of electrical power supply (not shown). Theconstant metered quantity of oil is then fed to a closed non-magnetictapered tube 36. A freely movable, magnetic restriction element 38 islocated within the tapered tube 36 for purposes hereinafter described.The oil then passes through the tap fitting 31 into return line 33,through fitting 27 into the return line 24. The usual bypass line 35with its check valve 37 are provided to bypass the control line fluid inevent of the malfunctioning of the pump 32 or stoppage in the taperedtube 36.

Magnetic induction coils 40 and 41 are positioned around and adjacentthe tapered tube 36 so as to be influenced by the rise and fall of themagnetic restriction element. These coils are connected as shown to themotor control portion 42 of the motorized control valve 20 in theheating fluid line and to a source of suitable electrical power supply43.

With reference to FIG. 2, the modification here shown consistsprincipally in employing a permanent magnetic fork 50 whose tines 5-1extend on each side of the nonmagnetic tapered tube 36. The fork 50 isbalanced on a knife edge or other suitable piv-ot arrangement 52 and itsextending arm 53 is arranged to open and close the relay contacts 54 and55. These relay contacts 54 and 55 are connected, as shown, to themotorized control 42 of the valve 20 and the source of electrical powersupply 43.

In the operation of the control device shown in FIG. 1, a small quantityof fuel oil is bled from the main line 24 and is passed to the positivedisplacement type pump 32 from which it is delivered to the non-magnetictapered tube 36 at a constant rate. This tapered tube 36 is sopositioned that the metallic and freely movable restriction element 3'8of magnetic qualities located therein is responsive to the force ofgravity and the internal friction or viscosity of the fluid movingthrough the tube. The magnetic restriction element in the tapered tube,with a constant rate of fluid flow, positions itself at that point .atwhich the internal friction or viscosity of the oil is balanced by theweight of the element. An increase in viscosity causes the element torise while a decrease in the viscosity will permit it to fall. Theinduction type relay 40, 41, 42, the magnetic field of which isconditioned by the position of the magnetic restriction element withrelation to the coils 40 and 41, will respond to the assumed position ofthe element to actuate a control 42 which in turn monitors the supply ofenergy to the fuel heater 14 through the motorized control valve 20. Ifthe magnetic element rises in the tapered tube because of an increase inviscosity, the magnetic field of the relay is changed and the relay andits control operates to increase the energy flow to the oil heater whichincreases the temperature of its contents. This increase in temperatureacts to reduce the viscosity of the oil discharging from the heater,thus allowing the magnetic element to return to its initialpredetermined position. Conversely, if the magnetic element drops belowits initial position because of reduced viscosity, the relay operates toreduce the energy flow to the oil heater, thus reducing the temperatureand increasing the viscosity of the oil. The median position of themagnetic restriction element 38 in the tapered tube 36 is adjustable tothat corresponding to the desired viscosity of the fluid passing throughthe system.

The principle of operation of the circuitry in FIG. 2 is identical tothat described above except that here we have a mechano-magnetic systeminstead of the electro-magnetic system of FIG. 1. As the magneticrestriction element 38 rises and falls under the variable viscosityconditions outlined above, the permanent magnetic fork 50 follows theelement 38 and its arm 53 makes contact with relay contacts 54 and 55,depending on the motion of the element 38. Obviously, as the element 38falls due to reduced viscosity, the fork 50 follows it and the armcontacts and closes the relay points 54. This results in reducing theenergy flow to the fluid heater and the viscosity thereof is increased.The converse follows. As before, the median position of the element 38may be adjusted by controlling the flow of fluid of the desiredviscosity through the tapered tube 36. A further finer adjustment ishere provided which consists of the movable pivot 52 being adjustable toeither center the arm 53 between the relay contacts 54, 55, or to assumesuch position with relation thereto as may be desired.

While the preferred embodiment of the invention, and an importantmodification thereof, have been described, it is to be understood thatthe description is illustrative only and there is no intention of beinglimited thereto. While my invention has been described, mainly, as beingapplicable to fuel oil systems, it is equally applicable to any systemwherein the viscosity of a fluid is a function of a controllabletemperature. Obviously, many modifications of my system may be suggestedby those skilled in the art. It is contemplated that all such may wellfall within the spirit of .the disclosed invention and the scope of theappended claims, wherein I claim:

1. In a fluid system having a main fluid conduit, variable heating meansconnected in said main conduit for heating said fluid and pump meansconnected in the main conduit for forcing the fluid therethrough, afluid viscosity control comprising:

a bypass fluid conduit connected to said main fluid conduit so as tobypass a portion of the fluid around a portion of the main fluidconduit;

a constant flow pump connected in said bypass conduit for maintaining aconstant flow of said fluid through said bypass conduit; and

means operatively connected to said bypass conduit for magneticallysensing the viscosity of the fluid flowing therethrough and forcontrolling the heat of the variable heating means as a function of saidviscosity.

2. A fluid viscosity control as claimed in claim 1 wherein:

the magnetic sensing means includes a tapered nonmagnetic tube connectedin said bypass conduit;

a freely movable magnetic restriction element within the tapered tubeand capable of moving longitudinally therein in response to theviscosity of the fluid flowing therethrough; and

means associated with the tapered tube and located exterior thereof forsensing the movement of the magnetic restriction element.

3. In a fluid system including a first conduit leading from a source offluid supply to a point of consumption, pump means interposed in thefirst conduit for forcing the fluid therethrough, a heating meansinterposed in the first conduit for regulating the temperature of thefluid passing therethrough, an infinitely variable source of energy forsaid heating means and control means associated with the source ofenergy for variably controlling the amount of energy supplied to theheating means, a fluid viscosity control comprising:

a second conduit leading from said point of consumption back to saidsource of supply;

pump means interposed in the second conduit for forcing fluidtherethrough at a constant rate; and

sensing means associated with said second conduit forelectromagnetically sensing the viscosity of said fluid, said sensingmeans capable of being connected with said control means for regulatingthe temperature of said fluid passing through said heating means as afunction of said viscosity.

4. A fluid viscosity control as claimed in claim 3 further characterizedby said sensing means comprising:

a tapered non-magnetic tube connected in the fluid circuit associatedwith said second conduit;

a magnetic restriction element suspended in the fluid within saidtapered tube, said element being free to move with respect to thelongitudinal axis of said tube and said element having a median positionin said tube established by the predetermined fluid viscosity actingagainst said element to counteract its weight;

means associated with said tube for creating a magnetic field coaxialwith respect to the longitudinal axis thereof;

a source of electrical power associated with said means; and

connection means for connecting said means with said source ofelectrical power and said variable control means for said source ofenergy for said heating means.

5. A fluid viscosity control as claimed in claim 4 wherein said meansfor creating said magnetic field consists of a pair of solenoid coilssurrounding said tapered tube, said coils being positioned on eitherside of said median position of said magnetic restriction element.

6. A fluid system as claimed in claim 3 further characterized by saidsensing means comprising:

a tapered non-magnetic tube connected in the fluid circuit associatedwith said second conduit;

a magnetic restriction element suspended in the fluid within saidtapered tube, said element being free to move with respect to thelongitudinal axis of said tube and said element having a median positionin said tube established by the predetermined fluid viscosity actingagainst said element to counteract its weight;

magnetic means partially surrounding said tapered tube, said magneticmeans being adapted for following said element in its motion along thelongitudinal axis of said tube;

electrical contact means carried by and associated with said magneticmeans;

a source of electrical power associated with said contact means; and

electrical circuit means for connecting said source of electrical power,said electrical contacts and said variable control means for said sourceof energy for said heating means.

References Cited by the Examiner UNITED STATES PATENTS 1/1928 Smith137-87 2/ 1936 Thomas 137--92 X 6/1943 Burns 137486 1/ 1946 Griesheimer137--92 X 6/1949 Brewer 137--486 X 6 2,715,705 8/ 1955 Barstow 73-209 X2,896,656 7/1959 Allen 13792 FOREIGN PATENTS 5 451,486 1948 Canada.

800,072 1958 Great Britain.

WILLIAM F. ODEA, Primary Examiner.

10 MARTIN P. SCHWADRON, ISADOR WEIL,

Examiners.

R. MASSENGILL, D. ZOBKIW, Assistant Examiners.

1. IN A FLUID SYSTEM HAVING A MAIN FLUID CONDUIT, VARIABLE HEATING MEANSCONNECTED IN SAID MAIN CONDUIT FOR HEATING SAID FLUID AND PUMP MEANSCONNECTED IN THE MAIN CONDUIT FOR FORCING THE FLUID THERETHROUGH, AFLUID VISCOSITY CONTROL COMPRISING: A BYPASS FLUID CONDUIT CONNECTED TOSAID MAIN FLUID CONDUIT SO AS TO BYPASS A PORTION OF THE FLUID AROUND APORTION OF THE MAIN CONDUIT; A CONSTANT FLOW PUMP CONNECTED IN SAIDBYPASS CONDUIT FOR MAINTAINING A CONSTANT FLOW OF SAID FLUID THROUGHSAID BYPASS CONDUIT; AND MEANS OPERATIVELY CONNECTED TO SAID BYPASSCONDUIT FOR MAGNETICALLY SENSING THE VISCOSITY OF THE FLUID FLOWINGTHERETHROUGH AND FOR CONTROLLING THE HEAT OF THE VARIABLE HEATING MEANSAS A FUNCTION OF SAID VISCOSITY.